Apparatus for stacking sheets



March 4, 1941. w. F. GRUPE 2,234,116

APPARATUS FOR STACKING SHEETS Filed March 12, 1958 6 Sheets-Sheet 1 72 845; Ticl.

INVENTOR,

gl- William FGru e 1 Z a b I H TORNEY March 4, 1941. w, GRUPE 2,234,116

APPARATUS FOR STACKING SHEETS Filed March 12, 1938 6 Sheets-Sheet 2 Tluzlfi. 55-2 )07 v 3 /?b l/c INVENTOR.

William FjGrupe ORNEY March 4, 1941.

W. F. GRUPE APPARATUS FOR STACKING SHEETS Filed March 12, 1938 6 Sheets-Sheet 5 INVENTOR William F. Grupe HI T'ORNEY March 4, 1941. w, F, GRUFFE 2,234,116

APPARATUS FOR STACKING SHEETS Filed March 12, 1938 I 6 Sheets-Sheet 6 v 504 40 J. .ll]. 42 I INVENTOR, Wllham I Gmpe Age/Q H TTORNEY Patented Mar. 4,1941

PATENT O FICE APPARATUS roa STACKING SHEETS William F. Grape, Lyndhurst, N. J., assignor to Champlain Corporation, a corporation of New York Application March12, 1938, Serial No. 195,463 17 Claims. '(Cl'. 271-76) This invention relates to apparatus for stacking individual sheets produced from a web as the web travels. In particular, the invention contemplates the provision of an apparatus for autotions may be pursued in the stacking of the sheets. to form segregated stacks,

It has been found that proper stacking of individual sheets-of material as they are delivered successively, one immediately following the other subsequent to production from the original web,

requires acertain time interval to elapse between delivery of each sheet and the one next followlowing to facilitate propersuperimposition of a delivered sheet on the stack being formed. A time interval adequate for accomplishing proper placement of the individual sheets on the stack may be most conveniently attained, without interference with production, ,by separating the sheets along the direction of sheet travel by distances proportionate to the time interval rea quired. Thismay be accomplished in various ways, but preferably by advancing each individual sheet in the direction of travel at a speed greater than the speed of the sheet that immediately follows.

30 In accomplishing stacking following the aforesaid regulated delivery, the sheets are superimposed on'e upon another while the formed portion of the stack is progressively withdrawn at a rate slightly greater than the rate of formation of 35 the stack. At intervals, corresponding to the desired height of the individual stacks, the stack or stacks formed are segregated from the stack or stacks to-be formed within and at the time interval between the delivery of two mutually ad- 40 jacent sheets.

The segregation is most efiectively accomplished by rapidly inserting separating means between the last formed stack and the stack next to be formed. For this purpose, separating means 45 may be placed ready for rapid advancement into functional position at the appropriate moment.

The separating means is preferably advanced toward sheet-receiving position at the same rate that the bottom of the stack being formed recedes from sheet-receiving position, and, at the appropriate moment, is rapidlyadvanced directly into sheet-receiving position.

By withdrawing the bottom of the stack being formed at a rate faster than the rate of stack formation, a clearance is provided between individual stacks. The rate of Withdrawal is desirably sufliciently fast to provide a clearance of magnitude capable of accommodatin the ter- 60 posed separating means as well as aifording free into the staking mechanism. The necessary min-' are dischargedfrom the producing machine and space for facilitatingultimate disposition of the successively segregated stacks.

In the instance of delivery of individual sheets to the stacking. mechanism substantiallyhorizontally, and especially when the material of the sheets is freely flexible and subject to buckling when unsupported, the'speed of deliveryof-the sheets must. be great enough to avoid, by the' principle of inertia, undue buckling as they pass imum speed will of course vary according to the degree of flexibility of the sheet material concerned and according to the lengths of the individual sheets, the speed necessarily increasing as the degrees of flexibility and the lengths increase.

Thus, it is apparent that among the primary objects of this invention are first to regulate delivery of individual sheets successively produced from a traveling web, and second to receive the delivered sheets in such manner as to build successively segregated individual stacks of superimposed sheets. Y a

Preferred apparatus employed in the carrying out of the invention is entirely automatic in operation. Advantageously, it is forthe most part operated directly from the machine employed in producing the individual sheets from the traveling web.

Characteristic of the particular apparatus here vdisclosed is its relative simplicity of structure, its

maintenance in correct operative order.

Briefly, roller means receive the sheets as they feed them, at web speed, to roller means operative at a speed greater than the operative speed of the receiving roller means, for subsequentdelivery to stacking mechanism. The relative grips 4 of the stated roller means are so regulated that a sheet, passing from one to the other, may be whisked along its path of travel at increased speed without retardation or injury by reason of g the differential speed of the roller means. 5

In the instances of substantially horizontal de- 4 livery to the stacking mechanism of freely'flexible sheets, that roller means which efiects ultimate delivery of the sheets to the stacking mechanism must motivate the sheet at a speed .sufll- 5o ciently great to prevent, by the principle of lnertia, undue buckling of the sheets as they are delivered. Accordingly, to anticipate such instances, means may be provided for motivating the stated roller means at the requiredv speed irrespective of the operativespeed of the producing machine. Thus, the usual lag, under the normal, of operative speed of the producing ma.- chine at the stages of starting and stopping of the producing machine, has no adverse affect on f at spaced intervals across the widths'of the propulsion rollers. They are so disposed as to maintain the sheets in proper feeding relation to the sets of feed rollers as the sheets pass from one .set to the succeedingset. Such supporting strips IS, in effect, provide a delivery table at the discharge end of the sheet-producing machine.

Pursuant to the second stage of operation, the so separated individual sheets l1, successively delivered, are superimposed one upon the other in the form of successively segregated individual stacks. The stacking is accomplished while progressively withdrawing the bottom of the stack being formed from sheet receiving position,

At the appropriate moment, i. e. upon the completion of formation of an individual stack,

the formed stack is segregated from the stack to be formed by the interpositioning of separating means. The stated interpositioning is accomplished at and within the time interval between the delivery of two mutually adjacent sheets.

The rate of progressive withdrawal of the bottom should be faster than the rate of stack formation by an amount suilicient to allow for the thickness of the separating means plus a clearance of at least an inch, the latter beingdesirable for facilitating removal of the formed stacks individually.

For accomplishing the second stage of operation in a most effective manner, it is preferred to employ apparatus comprising suitably disposed conveyor means correlated in operation with the operation of the sheet-producing machine.

Preferred apparatus, as illustrated in the drawings, includes endless conveyonmechanism disposed for vertical movement in sheet-receiving status adjacent the final set of feed rollers A vertically disposed box frame 20, comprising the four upright corner posts a, 20b, 20c, and 20d, supports a primary set 2| f endless conveyor chains, the set consisting of four individual endless chains 21a, 2|b, 2|c and 2|d, sprocketed adjacent the four corner posts 20a, 20b, 20c and 20d, respectively, and extending vertically from the lower portion of the box-frame to a location slightly above the location of sheet delivery.

A shaft 22 extending horizontally between the comer posts 20a and 20b adjacent the lower ends thereof is journaled therein for rotation, and a shaft 23, extending horizontally .between the low- -er ends of corner posts 20c and 20d, at a location horizontally aligned with shaft 22, is journaled therein for rotation. A shaft 24; extending horizontally between corner posts 290 and 2011 at a location vertically spaced above and aligned with shaft 22, slightly above the location of sheetdelivery, is joumaled therein, and a shaft 25, extending horizontally between corner posts 20c and 20d at a location vertically spaced above and 28 and 29, respectively, the latter being rigidly 70 mounted on shaft 24 at locations vertically aligned with the lower sprocket wheels 26 and 21, respectively. Likewise, endless chains He and 2|d at their lower ends are looped around and mesh with the sprocket wheels 30 and 3|, respectively, which are rigidly mounted on shaft 23 adjacent the corner posts 200 and 20d, and at their upper ends are'looped around and mesh with the sprocket wheels 32 and 33, the latter being rigidly mounted on the shaft at locations vertically aligned with the lower sprocket wheels and 3|, respectively. Thus, in the instant embodiment, there is formed a four-pointsuspension endless conveyor adapted to receive four cornered receptacles.

The endless conveyor 2| is actuated in correlation with the operation of the sheet-producing machine in such manner that inner portions of the component endless chains descend progressively and simultaneously to provide a conveying path of travel. To this end, the shafts 22 and 23 may have integral extensions 22a and 23a, respectively, journaled in the bracket arms 32 and 33, respectively. A horizontal shaft 34 is journaled in the bracket arms 35-| and 35-2, respectively, and is geared at its ends to the shaft extensions 22:; and 2311 by means of respective miter gearing indicated generally at 36-| and 36-2.

A chain drive 38 may transmit motion from a suitable connection with the sheet-producing machine (not shown), to a main drive-shaft 39, the latter being geared at one end by suitable worm gearing, as illustrated, to a crank-shaft 44, see Figs. 2, 3 and 10, journaled in a bearing support 4|. A connecting rod 42, having one end journaled on a crank 40a which is adiustably mounted in the diametric slideway 40-2a of the coupling member 40-2, the latter being rigidly mounted on crank-shaft 40 (Fig. 3), serves to reciprocate the drive arm. 43a of a suitable usual type of ratchet mechanism, indicated generally at 43 (Fig. 2). Such ratchetmechanism is mounted on the extension 23a. of shaft 23 and is operatively connected therewith for rotating shaft intermittently. Through connecting shaft 34 this intermittent motion is' transmitted to shaft 22, thus motivating the four endless chains Ma, 2 lb, 2|c and 2 Id, simultaneously.

' The eccentricity of crank 40a with respect to the crank-shaft 40 may be varied by means of the adjusting screw 40-3 to compensate for different thicknesses of web material used from time to time in the sheet-producing machine. Adjustment of screw 4l1-3 moves crank 4|la in its slideway 40-20. either toward or away from the axis of rotation of crank-shaft 40.

While. the above described mechanism has been found satisfactory for actuating the endless conveyor 2| in desired manner from the sheet-producing machine, the invention is by no means limited to its use. Other mechanism, as for instance a solenoid, or the device manufactured by The General Electric Co. commonly known as a Thruster automatically electrically controlled by the sheet-producing machine, may be advantageously employed for the same purpose.

Advantageously, an auxiliary set 45 of endless conveyor chains, comprising the component endless chains 45a, b, 45c and 45d, rises above primary set 2| of endless conveyor chains, and said chains have their lower ends looped around sprocket wheels 46, 47, 48 and 49, respectively,

and their upper ends looped around sprocket.

wheels 50, 5|, 52 and 53, respectively. The lower sprocket wheels 46, 41, and 48, 49 are mounted for free rotation onthe shafts 24 and 25, respectively, desirably immediately adjacent sprocket wheels 28, 29 and 32, 33, respectively.

The upper sprocket wheels 50 and 5| are rigidly mounted on a shaft 54 which extends horizontally between and is journaled in the upper ends of comer posts 28a and 20b of the box-. frame, and the upper sprocket wheels 52 and 53 are rigidly mounted on a shaft 55 which extends horizontally between and is journaled in.

the upper ends of corner posts 280 and 28d of the box-frame in horizontal alignment with shaft 54. The various shafts and sprocket wheels are aligned horizontally and vertically relative to one another as previously explained with respect to the various shafts and sprocket wheels of the primary set of endless chains. The four endless chains 45a, 45b," 45c and 45d of the auxiliary set 45 thus form a four-point-suspension secondary conveyor adapted to receive four cornered receptacles and to feed them into the primary conveyor 2 l The secondary conveyor 45 is normally actuated in correlation with the descending motion of primary conveyor 2|.v The inner portions of the component endless chains normally descend progressively and simultaneously at the same rate as do the inner portions of the component endless chains of the primary conveyor 2i to provide a conveying path of travel.

To this end, the lower sprocket wheel 48 of the secondary conveyor 45, see especially Figs.

3, Sand 10, is provided with a pin 58 extending rigidly from its inner face. A collar 5|, having a fork formation formed on its outer circumferential surface by two mutually spaced rigidly extending lugs 6M. and Nb, is rigidly mounted on shaft immediately adjacent sprocket wheel 48 in .such manner as .to.- receive the pin 68 in the fork formation between. the lugs Sid and 5|b.v

When shaft 25 is rotated by the rotation of sprocket wheels 32 and 33, collar 6| rotates therewith carrying lug Gla'into contact with pin 58.

Thereafter, during rotation of shaft 25, lug Gla normally maintains pressure contact with pin 68 and thereby simultaneously rotates sprocket wheel 48. I

The shafts 54 and 55 have integral extensions 54a and 5511., respectively. A horizontal shaft 56,

journaled in the bracket arms 5Il and 51-2, is geared at its ends to the shaft extensions54a and 55a by means of miter gearing indicated generally at 58 l and 58-4, respectively.

Because of the interrelated connections of the four component endless chains 45a, 45b, 45c and 45d, rotation of lower sprocket wheel 48, as above described, will actuate the entire set of endless chains of secondary conveyor 45 in the prescribed manner, i. e. at a rate equal to the rate of descent.

V of the primary conveyor 2|.-

The primary conveyor 2| is adapted to receive and support receptacles, see the receptacles 55, Fig. 3, at successively spaced locations along the length of its descending path. For this purpose, certain corresponding links of each of the component endless chains 2la, 2lb, He and 2ld are provided with fingers extending preferably integrally and perpendicular to the link lengths, into the path of receptacle descent. Such links are indicated at 55, see Figs. 3, tand 5, and form successively spaced sets of horizontally aligned fingers for receiving and supporting the receptacles. Their spacing in the respective endless chains depends upon the type of receptacles employed, the desired height of stacks, and the desired clearance between individual receptacles.

The receptacles 65 are preferably introduced manually into' the secondary conveyor at the open top thereof. For their support, supporting fin- 45b, 45c and45d forming sets of horizontally aligned supporting fingers. Operation of the fingers 61 and their associated mechanism will be discussed at length hereinafter. At the moment, suffice it to say that a setof supporting fingers 51 serves to receive a receptacle 55 and carry it toward and into sheet-receiving position at the top of primary conveyor 2|.

Feed of a receptacle 65 from secondary conveyor 45 directly into sheet-receiving position at the top of primary conveyor 2| is accomplished at and during the time interval between delive y of an individual sheet l1 and the individual sheet that next follows. For this purpose, the rate of descent of secondary conveyor 45 is suddenly increased, during the stated time interval, to a rate approximately proportioned one to one with the rate of production of individual sheets in the sheet-producing machine.

In attaining the desired correlation with the sheet-producing machine, mechanism may be mounted on the extension 54a of shaft 54 for operative connection with the main drive shaft.

The mechanism advantageously comprises a ratchet type connection with the main" drive shaft 7 39. A ratchet wheel 18,'see especially Figs. 3 and 7, having its outer circumferential surface configurated in such manner as to, provide a relatively small number of teeth 18a widely separated by substantially smoothvarcuate slideway surfaces 18b, each extending'from the' top of one tooth 10a to the bottom of a next adjacent tooth 18a, is rigidly mounted on the extension 540. of shaft 54 for rotation therewith in the direction of the arrow, Fig. 7. A pawl-supporting plate H is journaled on shaft 54 immediately adjacent ratchet wheel 18, and has an opposite end connected by the link 12 to one end of a bell crank 13, the

' bell crank being, journaled on a stub shaft 14,

- journaled for rotation in the bearing bracket I8 and is geared to an intermediate shaft 19 by miter gearing 88, the intermediate shaft 19 being journaled in a bracket support extending from frame side member l2a. A gear 8|, rigidly mounted'on an end of intermediate shaft 19, meshes with a pinion 82 rigidly mounted on main drive shaft 39. Thus, rotative motion is transmitted from main drive shaft 39 (which in turn receives its motion from the sheet-producing machine), through the above described gearing to eccentric carrying shaft 11, from where it is transmitted as reciprocatory motion to pawl-supporting plate H by means of the eccentric 11a, the connecting shaft 15, the bell crank I5, and link 12.

A stub shaft 83 extending rigidly from pawlsupporting plate II has journaled thereon a pawl 84 adapted to ride along the slideways 18b between teeth llla of ratchet wheel 18. A leaf spring 85, having one end pinned to pawl-supporting plate H, yieldably urges pawl 84 against the circumferential surface of ratchet wheel 18.

By reason of its rigid securement on shaft 54,

ratchet wheel 10 rotates in the direction of the related mechanism, with shaft 23, which is ro-z tated intermittently at desired speed from main drive shaft 39.

Pawl-supporting plate 1! rocks back and forth continuously on its pivotal mounting on shaft 54 by reason of its previously described operative connection with main drive shaft 39, and carries pawl 84 through the same reciproeatory path. Because the, connection with main drive; shaft 39 is geared approximately one to one with the production of individual sheets in the sheet-producing machine, while the operative connection of shaft 25 with main drive shaft 39 is geared at a difierent ratio, the reciprocative stroke of pawl 84 in the direction of rotation of ratchet wheel 19 is accomplished at a speed considerably above the speed of rotation of ratchet wheel 19. During the continuously intermittent rotation of shaft 54 in the direction of the arrow, see Fig. '7, pawl 84 rides inefl'ectually through its own reciprocative strokes on the circumferential surface of ratchet wheel 19, until it engages a tooth 19a upon a stroke which occurs in the direction of rotation of ratchet wheel 19. Upon such engagement, the pawl 84 pushes ratchet wheel 19, and therewith shaft 54 in the direction of rotation at a speed considerably increased over its normal speed of rotation. At the termination of this tooth-engaging-stroke, pawl 84 again reciprocates ineflectually over the circumferential surface of ratchet wheel 19 as the latter rotates until it once more engages a tooth 19a, whereupon the tooth-engaglng-stroke, at speed increased over the normal rotative speed of ratchet wheel 19, is repeated.

Increase in the rotative speed of shaft 54, as above described, eifects descent of secondary conveyor 45 at the increased rate during the time period of the tooth-engagingreciprocative stroke of pawl 84. 45, 41, 48 and 49 of secondary conveyor 45 are freely rotatable on their respective shafts, and because the distance between the two lugs 6I'a and Slb is sufllciently great toprovide uninterrupted advance of pin 69 during the increased speed of rotation of sprocket wheel 48, the'increased rate of descent of secondary conveyor 45 is possible without interruption of the normal operation of primary conveyor 2 I.

The sudden increase in the rate of descent of secondary conveyor 45 relative to the rate of descent of primary conveyor 2| accomplishes rapid feeding of a receptacle into sheet-receiving position on a set of supporting fingers GB at the upper end of primary conveyor 2| within the time interval occurring between the delivery of two mutually adjacent individual sheets l1 from the sheet-producing machine.

The aforedescribed component mechanical elements accomplishing the sudden increase in rate of descent of secondary conveyor 45 must be so related to one another and to the remainder of the stacking mechanism that the stated increased rate of descent occurs at a time interval between delivery of two mutually adjacent individual sheets and at a time when a receptacle is properly positioned in secondary conveyor 45 for feed directly into sheet-receiving position on primary conveyor 2|.

While the above described mechanism for attaining momentary travel of secondary conveyor 45 at a suitable velocity greater-than the normal velocity of travel thereof, has proved very satisfactory, the present invention in its generic aspect is by no means limited to its use. Other well known mechanism, such as a solenoid auto- Because the lower sprocket wheels 1 er oppositely to the projection of roller shaft matically'electrically' controlled by the sheetproducing machine, may be employed for the purpose.

The receptacles 65 may be manually placed on a set of horizontally aligned supporting fin- 5 gers 61 from the open top of a secondary conveyor 45, For attaining positive feed of the empty receptacles 65 into sheet-receiving 'position on primary conveyor 2|, the fingers 61 are made to articulate and are guided in their articulation with respect to their supporting chains, and have, in addition, locking fingers 99 correlated therewith, see particularly Figs. 4 and 5. Each locking finger 99 is articulatively mounted on an endless chain immediately above a support-' ing finger 61 for coaction therewith in jaw fashion to positively grip a received receptacle during its down travel. Thus, there are provided horizontally aligned sets of cooperating fingers at spaced'intervals along the conveying path of travel of secondary conveyor 45.

Each supporting finger 61 and locking finger 99 is preferably of substantially right-angle plate formation, and is pivoted at approximately its vertex portion to a side of the particular link of the particular endless chain concerned, by means of a stub shaft G1-l or 99-4, which is desirably an extension of a pivotal coupling between two individual links of the chain.

The stub shafts 61-l and 99| project outwardly from the particular chain links concerned at opposite sides thereof each stub shaft 99-l being spaced above its related stub shaft 51,-! a small distance suflicient to provide for jaw action between the two cooperating fingers mounted on the stub shafts.

Each supp rting finger 61 has one leg 1a. which projects into the path of travel of the conveyor proper during the descent of same and is adapted to receive and support one portion of a receptacle 65. The other leg 61!; depends from the vertex, i. e. location of pivot, and has rigidly secured thereto a roller shaft 51-4 which projects perpendicularly away from the chain proper. A pair of pins 81-3, 61-3 extend rigidly from the supporting finger 61, one on each side of the stub shaft 61-l, to embrace the chain proper in maintaining stability of positioning of the finger relative to its supporting chain.

Each locking finger 99 has one leg 99 which is arranged to project into the path oftravel of the conveyor proper at an appropriate time during the descent of same, being adapted to lock and hold the received receptacle tightly against the cooperating supporting finger 51. The other leg 99b extends upwardly from the vertex, i. e. location of pivot, and has rigidly secured thereto a roller shaft 99-2 which projects perpendicularly away from the chain prop- 51-2 of cooperating supporting finger 51. A pair of pins 99-4, 59-4 extend rigidly from the locking finger 99, one on each side of the stub shaft 99---I, to embrace the chain proper in maintaining stabilityof positioning of the finger relative to its supporting chain. The sets of coacting fingers, each set comprising a supporting finger 51 and a locking finger 99, are guided in their travel along the conveying path of secondary conveyor 45 in a manner to elfect cooperative articulation of the two fingers of the set relative to each other. For this purpose, a. set of guide plates, each comprising individual guide plates 9! and 92, is positioned adjacent the path of travel of each of" '1 the component endless chains a, 45b, 45c and 45d of the secondary conveyor 45, see particularly Fig. 10.

For supporting the sets of guide plates in rigid placement relative to the sets of coacting fingers on the respective component endless chains, bars 93 and 94 extend between and are rigidly secured to corner posts 29a and 29b, and corner posts 29c and 29d, respectively, at locations intermediate the upper and lower shafts 54 and 24, and the upper and lower shafts 55 and 25, respectively. Individual guide plates 9| and 92 of each set' are rigidly supported from either bar 93 or bar 94 by means of rigid securement to opposite sides of a supporting extension 950 of a bracket 95, brackets 95 being rigidly secured at appropriate locations on bars 93 and 94. The component guide plates 9| and 92 of each set are thus spaced apart, facing each other in mu-' tual opposition, on opposite lateral sides of the descending portion of a component endless chain of the secondary conveyor 45.

Each guide plate 9| is provided with a guide channel 9 l-l which runs vertically adjacent the free edge of the plate at -that face thereof proximate the particular chain concerned. The guide channel 9I-l has an upwardly divergihg throat 9l-la at the top for receiving the roller shaft 61-2 of a supporting finger 61, and for guiding it into the vertical guide channel proper, 99-I, as the supporting finger 91 descends from the topmost portion of its endless path down into the conveying path of travel of the secondary conveyor, see particularly Figs. 4 and 5. Engagement of the roller shaft 91-2 in the guide chan-" nel 9l-l during vertical descent of the supporting finger 61 swings receptacle-receiving leg 910 into horizontal receiving position and maintains itin such position throughout substantially the complete vertical descent. At the end of the vertical descent, when the endless chain executes an arcuate withdrawal from the conveying path of travel of the conveyor, roller shaft 61-2 passes out of the open lower end of guide channel 9l-l and allows supporting finger 61 to assume its natural free hanging position, in which receptaclereceiving leg 61a hangs back out of the conveying path of travel of the conveyor, At the time receptacle-receiving legs 61a withdraws from receptaole-supporting position, the supporting finger 61 has descended into horizontal alignment with the supporting finger 95 of .primary conveyor 2|.

, Thud'withdrawal of leg 51a of supporting finger 61 effects transference of load to the supporting finger 69, the withdrawal of receptacle receiving leg 91a providing an uninterrupted path of descent for the receptacle 65 on primary conveyor 2|. During the ascending portion of the path of travel of the endless chain, supporting finger 91 rides freely in an inoperative position.

Each guide plate 92is provided with a. guide channel 92-l extending along the'length of the plate'at that face thereof proximate the particular chain concerned. The guide channel 92-l has an upwardly divergent receiving throat 92-la at its upper end adjacent the edge of securement of the guide plate, the guide channel proper descending vertically therefrom to a lo-.

cation intermediate the upper and lower ends 75 channel proper, in vertical alignment with the channel 92-l, guides the descent of the locking finger along the conveying path of travel of the secondary conveyor 45. During the descent of roller shaft 99-2 along the vertically extending portion of guide channel .92-l proper, lookingleg 9911 will be elevated out of the conveying path of travel of secondary conveyor 45, thus, allowing uninterrupted placement of a receptacle 65 on a set of horizontally aligned supporting fingers 61. During the descent of roller shaft 99-! along portion. 92-") of guide channel 92-l, locking leg 99a will travel downwardly from its elevated position into locking coaction, in jaw fashion, with receptacle-receiving leg 91a of the supporting finger 61 with which it cooperates. During the' remainder of the descent of roller shaft 99-2 through lower portion 92-10 of guide channel 92-l, locking leg 99a will be maintained in locking position relative to receptacle-receiving leg 91a of supporting finger 6l,'and will be carried down into sthe conveyin path of travel of primary conveyor 2|. When roller shaft 99-2 passes out of the open lower end of guide channel 92-l, the arcuate withdrawal of its supporting chain will carry it in a gradual arcuate path out of the con-v veying path of travel of the primary conveyor 2|.

From the above, it is clear that after the empty receptacle 65 is received by a set of horizontally aligned supporting fingersi'l, it is locked in place during its descent into sheet-receiving position at the top of primary conveyor 2|, by the maintained pressure of the cooperatingset of horizontally aligned locking fingers 99. Whereupon it ispositively transferred to a set of horizontally aligned supporting fingers 96 of primary conveyor 2|, and the set of locking fingers 99 gradually withdraw from looking status.

For maintaining the component endless chains 45a, 45b, 45c and-45d of the secondary conveyor taut during the travel thereof, each is provided with an idler sprocket wheel 96 positioned intermediate upper and lower sprocket wheels. Conveniently the brackets 95 are each provided with an adjustable extension 95b in which the idler sprocket wheel 96 is journaled.

Likewise, for maintaining the component endless chains 2la, 2lb, 2lc and Zld of primary conveyor 2|,taut during travel thereof, each is provided with an idler sprocket wheel 91. Bracket arms 99, appropriately mounted on cross bars 99, one of which latter extends between and is rigidly secured to corner posts 29a and 295, the other extending between and being rigidly secured to corner posts 290 and'29d, serve to journal idler sprocket wheels 91 in proper relation to their respective endless chains.

For maintaining stiffness of the component endless chains of secondary conveyor 45, guide strips I99, one for each of the endless chains, may be properly positioned by securement between the horizontally extendingv and vertically spaced crossvbars I 9| and I92 at the outer ends of arms l92-l, l92- l and I9l-l, l0|l,rig1d.. ly mounted on the cross bars l92, l9l respectively, and between the horizontally extending and vertically spaced cross bars I93 and I94, at the outer ends of arms l94-l, Ill-l and 193-1,

to limit-stop positions against lugs INF-1a,

I03I, rigidly mounted on the cross bars I04, I03, respectively.

Likewise, for guiding the travel of the component endless chains of primary conveyor 2|, guide strips I-I, one for each of the endless chains, may be properly positioned by securement between the horizontally extending and vertically aligned cross-bars 99 and IOI at the outer ends of arms similar to I03--I and I04-I, and between the horizontally extending and vertically aligned cross-bars 99 and I03 at the outer ends of arms similar to the aforementioned.

To preclude motion of the primary conveyor 2I and secondary conveyor 45 other than through the actuation of the driving mechanism, brakes I05 and I06, respectively, are provided. the shaft I05 is mounted for braking action on the shaft 23, and is provided with a manually adjustable control I05-I. The brake I06 is mounted for braking action on the shaft 55 and is provided with a manually adjustable control I06-I.

Shafts 54 and 55 may be provided with hand wheels 54--I and-55I, respectively, for affording manual operation of the conveyor mechanism when desired.

The receptacles '65 are advantageously of open-tray formation having a depth approximately equal to the desired stack height, see particularly Fig. 3- They are provided with means for engaging the receptacle-supporting fingers 81 and 66, such means being, in the illustrated instance, the lateral flanges 65a, 6512.

To facilitate definite placement of receptacles 65 in secondary conveyor 45 through the open top thereof, and for guiding their descent toward, into, and through the conveying path of travel of primary conveyor 2|, back guide strips I01, I01 are provided adjacent the corner posts 20b, 20d in substantially vertical alignment therewith. They are supported at their upper ends by suitable rigid securement to the horizontally disposed cross bar I08, the latter extending between and being rigidly secured in brackets l08-I, I08-I which rigidly project from corner posts 20b, 20d. The strips I01, I01, advantageously extend down to a location adjacent the bottom of primary conveyor 2|.

Guide strips I09, I09 are provided along the length of the conveying path of travel of primary conveyor 2i, between guide strips I01, I01, for closing the open back end of the receptacles 65 as they descend through the stated path.

The individual sheets I! are discharged from the delivery mechanism toward the front end of the receptacles 65 with considerable force. A front plate IIO extends completely across the conveying path of primary conveyor 2| at the position of sheet delivery, thus providing a front closure for the sheet-receiving receptacle, and a buffer plate for the sheets as they are delivered. The front plate I I0 is journaled on a shaft I I0l by means of bearing ears IIO2, IIO2, the shaft IIOI being rigidly mounted in and extending between brackets 0-3, "0-3, the latter "being rigidly secured to corner posts 20a, 20c, respectively. The front plate III) is normally held in operative position by the spring IIO4 encircling an end portion of shaft IIO-l, the spring being anchored at one end to a collar IIO5, which is rigidly mounted on the shaft IIOI, and the other end of the spring being anchored in one of the bearing ears I I0-2. The pins Il0--6, IIO6 extend rigidly from the respective outer face of bearing ears I I02, I Ill-2,

0-111, of collars I Ill-I, I I0'I which are rigidly secured to shaft IIO-I. Thus, front plate IIO may be swung-downwardly when desired against the returning pressure of spring 0-4 5 for permitting access to the receptacle 65 in which the stack is being formed.

Knock-down arms III, preferably of light resilient metal, are rigidly secured on a shaft I I2 for up and down oscillatory motion, in and out of a receptacle 6-5, as the individual sheets I! are being stacked. The shaft H2 is J'ournaled in bearing arms I,I3 extending rigidly from the upstanding end frame member He of frame I2. The shaft 2- is connected by suitable means, such as the rod II4, Fig. 10, with the sheet-producing machine for actuation thereby, there being one up and down stroke of'the arms III for each sheet delivered. Such strokes are permitted by the spaced successive delivery of the individual 20 sheets.

Lateral jogger plates of a suitable usual type are indicated'generally. at 5. These may be provided at the location of stack formation to accomplish lateral registry of the superimposed sheets during the stacking operation. A back jogger plate of a suitable usual type, indicated generally at I I! (Fig. 2), is placed at a back location of stack formation;

The bottom of each receptacle 65 is slotted as indicated at 6, Fig. 10, to aiiord travel thereof past the knock-down arms III and the lateral jogger plates 5, as thereceptacles are fed into sheet-receiving position.

Individual sheets I! are successively delivered into a receptacle 65 which is suitably positioned on primary conveyor 2| for the reception thereof. As the sheets are superimposed, one upon another, in the receptacle with the aid of the knock-down arms III and jogger plates H5 and Hi, the receptacle travels downwardly intermittently but continuously in accordance with the descent of primary conveyor 2|.

It is to be noted that the speed of delivery of individual sheets I'I directly into the receptacle '65 is regulated by sets of feed rollers II, II, and that the operating speed of such sets of feed rollers may be determined as desired, independently of the speed of operation of the sheet-producing machine, by the independent motor I6. This in their delivery as would interfere with positive superimposition on the stack being formed.

In many cases, especially in those instances where the individual sheets delivered to the stacking mechanism have a tendency to buckle downwardly under their own weight, it has been found highly desirable to employ receptacles of the type illustrated in Fig. 11 and designated I20. Such receptacles are generally similar to the 'aforedescribed receptacles 65, but are each provided with a bottom I20a which slopes downwardly, as respects the horizontal, from sheet-receiving end to the front end. In addition, to prevent the stack of sheets from sliding forwardly out of the receptacle during descent in the primary conveyor, a front wall I20b is provided preferably perpendicular to the horizontal, i. e. at an angle less than 90 with the sloping bottom I20a of the receptacle.

Where receptacles of the above type are employed, the front plate H0 may be eliminated. Its function is accomplished by front wall I201). 75

' As'heretof ore described, primary conveyor 2| is correlated in its descendingmotion with the operation of the sheet-producing machine. By effecting a suitable correlation, the bottom of receptacle 65 in 'which'the stack is being formed may be made to descend faster than the stack is being 'formed. Thus, when the stack is completely formed, another receptacle 65, fed from secondary conveyor into sheet-receiving position on primary conveyor 2| and in turn intermittently and continuously descending during the formation of a stack therein, may be spaced from the preceding receptacle a distance suflicient to afford ready removal of one with respect to the other.

By successively introducing receptacles 65 into secondary conveyor 45, atthe appropriate times during operation of the sheet-producing machine, to replace the receptacles fed into primary conveyor 2|, individual stacks of sheets are formed successively and continuously and are successiyely and continuously segregated. The completely formed individual stacks may be removed from the lower portion of primary conveyor 2| as desired.

Endless chain conveyors have proved very satisfactory for accomplishing feed of sheet-receiving receptacles into sheet-receiving position and 'for removing the same from sheet-receiving position. In its generic aspect, however, the invention is not limited to their use specifically. Other well known types of conveyor means may be employed to substantially like efiect for accomplishing the purposes of the invention.

Because of the aforedescribed interrelationship of operation between the sheet-producing machine and the stacking mechanism, a desired definite number of sheets may be predetermined for the respective stacks.

While the illustrated apparatus involves the delivery and stacking of a single longitudinal 'successionof individual blanks extending completely across the width of the web which is operated upon by the sheet-producing machine, it is distinctly within'the purview of the invention to. provide for the delivery and stacking of a plurality of longitudinal successions 9f individual blanks disposed mutually adjacent laterally across the width of the web-and advantageously formed by slitting the web longitudinally-by correspondingly compartmenting the receptacles 8 5 or I29 across their respective lateral extents, ii e. widths, by supplying a jogger plate I i0 and a knock-down arm I l l for each compartment, and

the invention or sacrificing any of its advantages. 7

I claim: 1. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals,

comprising primary conveyor means adapted to carry sheet receiving means at spaced intervals along its lengthfor receiving the sheets delivered thereto; secondary conveyor means disposed in substantial alignment with the primary conveyor means and arranged for travel along a path merging at one end into the path of travel of said primary conveyor means; means for normally actuating both of said conveyor means in the same direction and at substantially the same speed; and means associated with said secondary conveyor means for supporting sheet receiving means and feeding them into said primary conveyor means.

2. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising primary conveyor means adapted to carry sheet receiving means at spaced intervals along its length for receiving the sheets delivered thereto; secondary conveyor means disposed in substantial alignment with the primary conveyor means and arranged for travel along a path merging at one end into the path of travel of said primary conveyor means; means associated with said secondary conveyor means'for supporting sheet receiving means and feeding them into said primary conveyor means; means for normally actuating both of said conveyor means substantially in synchronismyand means for actuating caid secondary conveyor means at an increased speed at and during predetermined time intervals.

3.- Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising primary conveyor means arranged for substantially vertical descending travel and adapted to carry sheet receiving means at spaced intervals along its length for receiving the sheets delivered thereto; secondary conveyor means disposed above said primary conveyor means for substantially vertical descending travel along a path merging at its lower end into the upper end of the path of travel of said primary conveyor means; means for normally actuating both of said conveyor means in the same direction and at substantially the same speed; and means associated with said secondary-conveyor means for supporting sheet receiving means and feeding them into said primary conveyor means.

4. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising primary conveyor means arranged for substantially vertical descending travel and ;adapted to carry sheet receiving means at spaced intervals along its length for receiving the sheets delivered thereto; secondary conveyor means disposed above said primary conveyor means for substantially vertical descending travel along a path merging at its lower end into the upper end of the path of travel of said primary conveyor means; means associated with said secondary conveyor means for supporting sheet receiving means and feeding them into said primary conveyor means; means for normally actuating both of said conveyor means substantially in synchronism; and means for actuating said secondary conveyor means at an increased speed at and during predetermined time intervals.

'5. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising primary conveyor means arranged for substantially vertical descending travel and adapted to carry sheet receiving means at spaced intervals along its length for receiving the sheets delivered thereto; secondary conveyor means disposed above said primary conveyor means for substantially vertical descending travel along a path merging at its lower end into the upper end of the path of travel of said primary conveyor means; means associated with one of said conv y me s for pp g sheet receiving means; and guiding means for said one conveyor means, and including means for releasing said gripping means so that the sheet receiving means may be removed therefrom 6. In combination with a machine which produces individual sheets from a web and with delivery mechanism associated therewith for spacing delivery of the individual sheets at intervals as they are discharged from the machine, stacking mechanism comprising primary conveyor means disposed adjacent the delivery mechanism and adapted to carry sheet receiving means at spaced intervals along its length for receiving sheets as they are delivered from the delivery mechanism; secondary conveyor means disposed in substantial alignment with said primary conveyor means and arranged for travel along a path merging at one end into the path of travel of said primary conveyor means; means for normally actuating both of said conveyor means in the same direction and at substantially the same speed; and means associated with said secondary conveyor means for supporting sheet receiving means and feeding them into said primary conveyor means.

7. In combination with a machine which pro- 5 duces individual sheets from a web and with delivery mechanism associated therewith for spacing delivery of the individual sheets at intervals as they are discharged from the machine, stacking mechanism comprising a frame substantially vertically disposed adjacent the delivery end of said delivery mechanism; a primary conveyor disposed in a lower portion of said frame for substantially vertical descending travel, said primary conveyor extending into sheet-receiving position relat ve to said delivery mechanism; a secondary conveyor disposed in an upper portion of said frame for substantially vertical descending travel along a path merging at its lower end into the upper end of the path of travel of said primary conveyor; means associated with said primary conveyor for supporting sheet-receiving receptacles at spaced locations along the descending path of travel thereof; means associated with said secondary conveyor for supporting sheet-receiving receptacles and feeding them into said primary conveyor; means for actuating said primary conveyor at a predetermined speed correlated with the speed of sheet delivery thereto; .means for normally actuating said secondary conveyor in synchronism with said primary conveyor; and

means, correlated with sheet delivery, for actuating said secondary conveyor at an increased speed at and during predetermined time intervals.

8. The combination recited in claim '7 wherein the primary and secondary conveyors comprise sets of endless chains, respectively.

9. The combination recited in claim 7 wherein the primary and secondary conveyors comprise sets of endless chains respectively, and the means for supporting sheet-receiving receptacles comprise sets of horizontally aligned fingers spaced at intervals along the lengths of the endless chains.

10. The combination recited in claim '7 wherein the primary and secondary conveyors comprise sets of endless chains-respectively, and the means for supporting sheet-receiving receptacles comprise sets of horizontally aligned fingers spaced 70 at intervals along the lengths of the endless chains, the sets of horizontally aligned fingers associated with the secondary conveyor comprising individual sets of cooperating fingers, each set consisting of a supporting finger articulatively mounted relative to each other for coaction in feeding received receptacles into the primary conveyor.

11. In combination with a machine which produces individual sheets from a web and with deilvery mechanism associated therewith for spacing 5 delivery of the individual sheets at intervals as they are discharged from the machine,'stacking mechanism comprising a frame substantially vertically disposed adjacent the delivery end of said delivery mechanism; a primary conveyor dis- 10 posed in-alower portion of said frame for substantially vertical descending travel along a path merging at its lower end into the upper end of the path of travel of said primary conveyor, the lower portion of said primary conveyor and the 16 upper portion of said secondary conveyor being mounted on common shaft means; means associated with said primary conveyor for supporting sheet-receiving receptacles at spaced locations along the descending path of travel thereof; 20 means associated with said secondary conveyor for supporting sheet-receiving receptacles and feeding them into said primary conveyor; means for actuating said primary conveyor at a predetermined speed correlated with the speed of sheet 25 delivery thereto; means associated with said common shaft mounting for normally transmitting motion of the primary conveyor to the secondary conveyor, said means providing for limited motion of the secondary conveyor at a greater than 30 normal velocity; shaft means associated with the secondary conveyor for rotation thereby, normally, and for drive thereof at predetermined intervals; ratchet means-rigidly mounted on said shaft means; a drive member for said ratchet 85 means, said drive member being correlated with the sheet-producing machine for predetermined reciprocation continually during operation of the latter, and, further, being adapted to engage said ratchet means only at and during predetermined 0 reciprocative strokes, said ratchet means and drive member being adapted to actuate said shaft means, and therewith said secondary conveyor during said predetermined intervals at-a velocity greater than normal. 45

12. In combination with a machine which produces individual sheets from a web and with delivery mechanism associated therewith for spacing delivery of the individual sheets at intervals as they are discharged from the machine, stacking 5o mechanism comprising a frame substantially vertically disposed adjacent the delivery end of said delivery mechanism; a primary conveyor disposed in a lower portion of the frame for substantially vertical descending travel, said primary conveyor 55 comprising a set of four substantially vertically disposed endless chains spaced apart mutually in horizontal alignment to provide four-point suspension for receptacles received by said conveyor, said set of endless chains extending up- 60 wardly into sheet-receiving position relative to the delivery mechanism; horizontally 'disposed shaft means interconnecting the lower loops of said endless chains to one another for simultaneous actuation; sprocket wheels rigidly mounted on said shaft means and engaging said lower loops of the endless chains; horizontally disposed shaft means interconnecting the upper loops of said endless chains to one another; sprocket wheels rigidly mounted on said last named shaft means and engaging said upper loops of the endless chains; a secondary conveyor disposed in an upper portion of the frame for substantially vertical descending travel along a path merging at its lower end into the upper end of the path of u travel of said primary conveyor, said secondary .conveyor comprising a set of four substantially vertically disposed endless chains spaced apart mutually in horizontal alignment to provide fourpoint suspension for receptacles received by said conveyor, the last named set of endless chains extending downwardly substantially into sheet-receiving position relative to the delivery mechanism, the lower loops of the component endless chains thereof being interconnected by the said shaft means which serve to interconnect the upper loops of the component endless chains of the said primary conveyor; sprocket wheels mounted for free rotation on the last named common shaft means and engaging said lower loops of the component endless chains of the secondary conveyor; horizontally disposed shaft means interconnecting the upper loops of the component endless chains of the secondary conveyor; sprocket wheels rigidly mounted on the last named shaft means and engaging said upper loops of the component endless chains of the secondary conveyor; re-

. ceptacle-reoeiving fingers spaced at corresponding intervals along the lengths of the component endless chains of the primary conveyor forming sets of horizontally alignedreceptacle-receiving fingers spaced at intervals along the descending path of travel of the primary conveyor proper; sets of cooperating fingers, comprising a lower receptacle-receiving finger and an upper locking finger articulatively mounted relative to each other for coaction in feeding received receptacles into the primary conveyor, spaced apart at corresponding intervals along the lengths of the component endless chains of the secondary conveyor forming sets of horizontally aligned sets of fingers spaced at intervals along the descending path of travel of the secondary conveyor proper; guide plates associated with each of the component endless chains of the secondary conveyor for engaging portions of the fingers of each of said sets of fingers to guide the cooperative articulation of said fingers; drive means connected with the said shaft means which interconnect the v lower loops of the component endless chains of --velocit y; a ratchet wheel rigidly mounted on the shaft means which interconnects the upper loops of the component endless chains of the secondary conveyor, said ratchet wheel having teeth spaced by a distance determined by the time interval elapsing between delivery of two mutually adjacent sheets from the sheet producing machine; a drive pawl for said ratchet wheel mounted for continuous reciprocating in the direction of normal rotation of the ratchet wheel at a speed correlated with the operating speed of the sheetproducing machine, said drive pawl being adapted to reciprocate ineffectually between two mutually adjacent teeth of the ratchet wheel as the ratchet wheel rotates normally, and being adapted to engage a tooth of the ratchet wheel at intervals for increasing the velocity of rotation of the ratchet wheel to equal the velocity of a forward reciprocative stroke of the pawl at and during said reciprocative stroke.

13. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals,

comprising conveyor means; means for actuatingsaid conveyor means at a predetermined speed; means secured to said conveyor means for gripping a sheet receiving receptacle; and guiding means for said conveyor means, and including means for actuating said gripping means as the conveyor means moves therethrough.

14. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising primary conveyor means adapted to carry sheet receiving means at spaced intervals along its length for receiving the sheets delivered thereto; secondary conveyor means disposed in substantial alignment with the primary conveyor means and arranged for travel along a path merging at one end into the path of travel of said primary conveyor means; means associated with said secondary conveyor means for supporting sheet receiving means and feeding them into said primary conveyor means; and means for gripping said sheet receiving means while they are carried by said secondary conveyor means and releasing them asthey are fed into said primary conveyor means.

15. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising conveyor means; means for actuating said conveyor means at a predetermined speed; means associated with said conveyor means for gripping a sheet receiving receptacle; and means for releasing said gripping means at a predetermined point in the travel of said conveyor means.

16. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals, comprising conveyor means; means for actuating said conveyor means at a predetermined speed; means associated with said conveyor means for gripping a sheet receiving receptacle; means for actuating said gripping means to cause it to grip a sheet receiving receptacle at a predetermined point in the travel of said conveyor means; and means for releasing said gripping means at a predetermined point in the travel of said conveyor means. i

17. Apparatus for stacking sheets which are continuously delivered thereto at spaced intervals,

comprising primary conveyor means adapted to carry sheet receiving means at spaced intervals along its length for receiving the sheets delivered thereto; secondary conveyor means disposed in substantial alignment with the primary conveyor means and arranged for travel along a path merging at one end into the path of travel of said primary conveyor means; means associated with said secondary conveyor means for supporting sheet receiving means and feeding them into said primary conveyor means; means'for gripping said sheet receiving means while they are carried by said secondary conveyor means and releasing them as they are fed into said primary conveyor means; means for normally actuating both of said conveyor means substantially in synchro- 

